Skin cancers are usually classified into non melanoma and malignant melanoma.
22.3.1 Non-melanoma Skin Cancers
Basal cell carcinoma (BCC) and squamous cell (SCC) are the most common non melanoma skin cancers. SCC is more aggressive than BCC and has the potential to metastasis. The main cause of these skin cancers is overexposure to Ultraviolet radiation. Risk factors include light-coloured skin (e.g albinism), previous burn and immunosuppression eg after transplant or HIV infection
Diagnostic Criteria
The most common warning sign of skin cancer is a change in the appearance on exposed areas of the skin, such as a new growth or a sore that will not heal. Occasionally, such changes may appear on an old burn area.
Investigations
- None if lesion is small
- Local x-ray if bone involvement is suspected
- CXR if undifferentiated tumour
- Biopsy – preferably excisional biopsy where possible for histology
Management
Surgery is the primary treatment. Wide local excision that achieves negative surgical margins is adequate. Skin grafting may be required after surgery. Amputation sometimes is done for palliation. Locally destructive methods such as curetting or cryotherapy may be employed
Radiotherapy
Indication: Positive margin, high grade disease or inoperable tumour.
Pharmacological Treatment
Topical 5-fluorouracil for very superficial lesions or carcinoma in situ
Systemic chemotherapy is given for palliation in advanced stage or as radio sensitizer.
Note: Prevention or early detection is through frequent self–health check–up or screening exercise and prompt treatment of early skin lesions. For light skinned people–avoid UV light
22.3.2 Malignant Melanoma
Diagnostic criteria
History of a pre-existing naves which has changed recently –itching, colour change, increase in size, satellite lesions, elevated surface, ulceration and/or oozing.
Investigations
- CXR or CT Scan
- Abdominal pelvic CT Scan
- PET CT when available
- Excisional biopsy of suspicious lesion for histopathology
Staging: Clark’s or Breslow classifications are used. Tumour size closely correlates with prognosis. Detection/ prevention: Frequent self –check up or screening exercise and prompt treatment of naves
Management: Surgery is the primary treatment.
- Wide local excision and graft
- Amputation sometimes for advanced useless limb
Pharmacological Treatment
Dacarbazne IV 250mg/m2 Day1–Day 5 every 3 weeks for 4 cycles
OR
Temozolomide (PO) 200mg/m2 Day 1–Day 5 every 4weeks
Radiotherapy used for palliation if:
- Lesion is inoperable. May use large fractions: 30Gy/6F/1 wk
- Excision margins are involved or very close
- Palliative intent (brain mets, fungation or profuse bleeding, bone pain etc)
22.3.3 Kaposi’s sarcoma (KS)
It is a malignant tumour of angio–formative cells usually starting from the skin but occasionally involving many other organs of the body. Kaposi sarcoma can be primarily categorized into four types: epidemic of AIDS–related, immunocompromised, classic or sporadic, and endemic (African). Here we have non AIDS related (endemic) KS and AIDS related (epidemic) KS where the late is more common 80–85%.
Diagnostic criteria
KS presents as a firm, dark brown nodules or plaque in the skin. Usually more on the limbs
In young children and those with immunodeficiency it presents as wide spread lymphadenopathy with or without skin lesions. Presence of B symptoms (fever, sweating and weight loss) is commonly associated with epidemic type. Clinical course can be indolent especially endemic KS or aggressive.
Investigations
- FBC,LFTs, Urea & Creatinine, HIV test (if positive CD4 count and viral load
- CXR, abdominal pelvic ultrasound or CT scan of chest, abdominal pelvic CT, Bronchoscopy and Endoscopy
- Skin biopsy for histological confirmation
Note: Histological appearance for all types is the same
Staging of KS: Epidemic Kaposi sarcoma use AIDS clinical trials group (ACTG) system and for endemic/classical Kaposi sarcoma use Mitsuyasu classification system
Management:
Treatment is palliative irrespective of type and stage hence careful assessment and decision is required to choose the best palliative treatment. ARVs should be initiated in epidemic KS patients who have not started the treatment. Choice of palliation depends on clinical presentation and patient general condition.
Radiotherapy: Is the best palliative treatment in symptomatic patient with local or extensive disease.
- 8Gy single fraction for disease on limbs or lower half body
- 6Gy single fraction for upper half body
- Dose of 9Gy/3# is usually prescribed for lesions elsewhere.
Pharmacological Treatment
Palliative chemotherapy is usually given in patient with generalized disease. Commonly used regimen is ABV.
- Adriamycin IV 25 mg/m2 Day1 + Bleomycin IV 10 IU/m2 Day1+Vincristine IV 1.4mg/m2 (max.2mg)Day1 Give every 3 weeks for 6 –8 cycles
- Paclitaxel IV 100mg/m2 Day1 every 2 weeks or docetaxel 75mg/m2 day1 every 3 weeks is given for persistent or recurrent after ABV.
